Centrifugal liquid crucible



Sept. 18, 1928. Y 1,684,800

J. MAXIMQFF ET AL CENTRI FUGAL LIQUID CRUCIBLE Filed Oct. 25, 1926 2 Sheets-Sheet 1 Fig.1.

//Vl/EN r025 d0 vE/mL MAX/M0FF MR/A 575401 of Cosvu NEE M/vcz/vr HTTORNE Y6 Sept. 18, 1928 J. MAXIMOFF ET AL CENTRIFUGAL LIQUID CRUC IBLE Filed Oct. 25, 1926 Fig.2.

52510107111057 my Illa/i=2 IIIIIIIIIIIlIIWIIIIII/llfl 2 Sheets-Sheet 2 [mill/11111111111 MR! SPELL? DE 603771 WEE M/VCE/VT BY 772M494 Patented Sept. 18, 1928; I

PATENT OFFICE.

IUVENAL IAXIMOFF LAND MARIA STELLA. mc COSTA, mil! VINCENT, OI HUNINQUE,

' IBANOE.

GENTBIFUGAL LIQUID (ZBJII'(ItIIZIBIiIE.

Application filed October 23, 1926, Serial no. 143,682, and in France December 24, 1925.

Certain physical or chemical operations are very diflicult to carry out and some of them are even impossible to realize, because vessels do not exist for the bodies treated,

5 capable of resisting either physical cond tions to which they are subjected, or to the very action of said bodies. By way of example can be citedthe melting of quartz.

It has been up to now ossible to carry out I this latter 0 eration on y in crucibles made of zircon w ich, whilst being very costly can only be used once, or in crucibles made of platinum-iridium which are excessively dear. 4

A process for the melting of quartz has also been proposed, according to which a rod of graphite is arranged in the axis of a vertical tube made of clay, the rod being heated,preferably, electrically, and the sand is poured in the annular space provided between the graphite rod and the clay tube. This process has the disadvantage of producing impure quartz, containing carborundum (CSi) and air and oxygen bubbles which'are included in the viscous mass and cannot evolve. Moreover, the quantity of quartz melted per unit of time is very small and does not allow the manufacture of articles of substantial dimensions.

The present invention has for object. to overcome the above objections and above treatments or reaction, and substantially consists in replacing the solid cruciwhich the required shape is given by the,v

combined action of centrifugal force and yt Y i In fact, it is known that when a liquid contained in a solid casing is caused to rotate, the inner surface takes the shape of a paraboloid under the simultaneous action of 4 centrifugal force and gravity.

When two liquids of difierent specific weights rotate together, the heavier, after attaining a certain speed comes to the exterior of .the other liq id and acts as a casing or envelope for the same.

roduce' practical vessels capable of resisting the bles by a liquid crucible constituted by a' a ring or annulus. and the lighter liquid comes in contact with the bottom of the vessel, this allowing it to flow away through an orifice of this vessel.

The accumulation of the heavier liquid at the center of the apparatus cannot take place, owing tothe fact that the amount of movement of this heavier liquid is several j times greater than the amount of movement of the lighter liquid, and also owing to the arrangement, on the 'walls of the crucible, of flutes for retainin the heavy liquid.

Owing to the app ication of these properti es,it is possible, in accordance with the' invention, to melt a body such as quartz within a liquid crucible, preferably made of molten metal, this metal can be copper,

manganese or chromium.

The said liquid crucible is formed within a casing comprising a rigid metal wall and a refractory coating.

The invention is also characterized by the special arrangements of the apparatus.

It is provided with heating means for bringing the bath of metal to the required condition of fluidity and supplying the heat necessary for the reaction. Preferably, the heating is eflected electrically by means of eddy currents. i

These currents are generated by one or more'conductors wound in a spiral and forming one or more layers about the apparatus; the said conductor comprises a pipe which serves at the same time forsupplying air,-

The air, water or oil for cooling purposes is fed by a system of distribution comprising crowns, rotating'with the rotary part of theapparatus, and fixed crowns; the joint between these crowns is so arranged that the parts in contact tend to be each other by the pressure 1 The system of distribution of air, water these currents to act elfipressed against (x ratus.

or oil serves also for the distribution of the electric current and the arrangements of the friction parts and elements through which pass the current are such that large'cross sections are offered to the passage of the current.

The apparatus is completed by means permitting to increase the speed of rotation of the heavier body at the time it is desired to drive out the lighter body from the apparatus, so as to allow the lighter liquid to come in contact with bottom of the appa- In order that the invehtion may be clearly understood, a form of construction of the said apparatus is illustrated, but by way of example only, in the accompanying drawing in which: R

Fig. 1 is a vertical section of the new apparatlls.

Fig. 2 is a horizontal section.

Figs. 3 and 4 are detail sections.

As illustrated in the drawing, the apparatus consists in a metal box 6r casing an, internally coated with a refractory lining I) made of magnesia, quick lime, etc.

The whole constitutes the solid crucible within which is formed the liquid crucible;

for that purpose this solid crucible is rotatably mounted on ball rings 0 d and it can be driven by means of one or more pinions gearing with a toothed ringa rigid with the box a.

This rotary structure, or rotor, is completely enclosed in an external casing comprising a cylinder 7, made ofc a material which is a bad conductor of heat," through which pass one or morepipes 9 into which is sent air, water or oil, for cooling the said external-casing. The cylinder is provided with a top or cover f and a bottom F.

The space a is filled with oil, so that all the ball bearings and gears run in oil. The latter is cooled by its contact with the coolmg plpes g.

The interior of the crucible 1) presents a concave bottom, the central part of which is raised, as shown in the drawing, forming a prO ecting' duct made of or covered with z rcon and adapted to facilitate the evacuation of the body treated. At the upper part, a boss it prevents the molten metal from rismg too high. At a certain distance from the side wall is arranged a cylinder '5, made of refractory material, leaving between it andthe lining 6 two annular intervals or spaces 7' into which can enter the molten metal u constituting the liquid crucible. This 1- inder i isconnected to the solid crucible y bonds as few in number and as narrow as possible so as to leave an easy access for the metal 10.

Through m'etal pipes the cylinder 11 pass one or more is, wound in a helix,-forming a winding, in one or more layers, which serve to feed the single phase,'two phase or three phase alternating current generating the eddy currents,

air or another fluid for cooling purposes. It results from the arrangement of .the conductor k that the metal contained in the annular spaces j is in the field of the currents and highly heated. Owing to the fact that the'metal is thus brought about the conductor la, the electromagnetic losses are avoided. 4

The ends of the tube lead to annular cavities Z, m formed by a combination of rotating crowns or rings rigid with the rotor, and of fixed crowns or rings. The air, or any other fluid, is brought into one of the cavities by a conduit 1 and led away by another conduit m In case of polyphased currents, the crowns or rings will used in nular cavities; a d signates a portion of the 1 metallic bottom onwhich are secured, by means of bolts 0 passing through insulating members 0 rings p shown in side view in the drawin these rings are in contact through sur ace 9 (the profile of which is in the shape of an inverted V) with a ring 39 (the profile of which is of U-shape) which is fixed and in which opens one of the pipes Z supplying'air or anyother fluid. The contact surfaces 9 are lubricated under pressure by the oil of the bath a (Fig. 1) and particularly by the oil under pressure supplied to the surface 9 through the openings provided in the ring 1). i I

The otherannular cavity is similar.

The admission of the current is effected through the member 39 on'which rub two arms r a spring 1* tending to space apart the said arms 9, thus placing them inlelectrio connection, as shown in Figs. 3 and 4.

For preventing the passage of current to the bottom 0, the conducting. members are separated from the bottom so by insulating parts 0 made of mica for instance.

The apparatus further comprises a plug a, normally closin the bottom of the apparatus and capa le of being moved away therefrom at the required moment. A pneu matic control has been illustrated by way of example for producing the movement of this lug. For that purpose, the said plug is rigi with a piston 8 moving in a cylinder 8 and compressed air can be sent above or beand which allow also to bring low the piston for lowering or raising the chimedes screw receiving the material from an elevator hermeticall enclosed in a casing'. A tube 'v supplies ydrogen or another gas, when the 1n this gas.

The operation is as follows :7 The current is fed to the apparatus and passes through the members p and 1' (Fig. 3) and through the conductor is; the eddy currents generated produce a high tempera ture which ensures the melting of the metal a. The rotor is caused to rotate; under the combined action of centrifu a1 force and gravity, the molten metal ta es the shape ofa paraboloid, as indicated in the drawing, so that it constitutes the liquid crucible in which thedesired'reaction can take place. Air'is exhausted from the apparatus, if this ,hasnot already been effected, by displacing it by a current of nitrogen or other suitable gas, supplied by the conduit '0.

The material'tobe treated (quartz or pure sand to be melted) is introduced into the ap'- paratus. This material being subjected to a very high temperature,,i s melted. During the entire operation, the air or Iother .fluid supplied by the pipe 1 passes in the tube In and prevents the wall ifromreachin a too high' temperature which would iminish the electroconductibility of the tube 7:. The wall a is coolel by'the oil' bath 0 and the latter is cooled in its turn byb the circulation of cold water in the tu e' :4

en the quartz is sufiiciently fluid and liquid and it 1s desired to cast it, the is increased so-that the liquid 11. takes the shape of an annulus or ring and that the liquid 2 may thus reach the solid bottom and I the tap hole.

. of oxi V40 -The roduct obtained can contain traces d d of lead or of silicium, but not to the extent of rendering it unsuitable for the uses for which it is intended: laboratory or cooking a paratus, replacement of cast-iron stones, 0 water conduit pipes, etc.

The invention is applicable whenever it is 1m ssible to use solidcrucibles, either for tec ical reasons for instance owing to the chemical aflinity betweenfthe substance of the crucible and that of the liquid, or for financial reasons, when the price of the ma 'terial of the solid crucibles is too hi h..

i The invention canbe realized accor 'ng to i any modification based on the above-mentioned principles and all the details of ex- Clalms fractory contain molten 'metahto form the crucible, an electrical conductor embedded" in said ecution can be varied according) to circumstances without do ,arting there y from the principle of the and invention. 1

' 1. An apparatus for formi liquid crucibles, comprising a vesscl-provi ed with a reinin'g, said vessel being adapted" to lininggand means for rotating the vessel.

operationmust be carried outv window glass, construction of a 2. An apparatus for forming liquid crucibles,.comprisin a vessel provided with a refractory liningfiiaving a concave bottom and an annular inwardly projecting member, an

electrical conductor embedded in the said member, and means forfrotating the vessel. A 3. An' apparatus for-forming liquid crucibles, comprising a vessel provided with a refractory lining having a concave bottom and provided with an annular and inwardly projecting member, passages opening into the vessel being formed between the body of the lining and the inwardly projecting member, an electrical conductor in said member,

and means for rotatingthe vessel.

4. An apparatus for formin liquid crucibles, comprising a vessel having a concave bottom and adapted to contain molten metal to form the crucible, heating means in the wall of the vessel, a jacket spaced from the vessel, a cooling medium in the jacket, and means for rotating the vessel. V

v 5.- Anapparatus for forming liquid crucibles, comprising a vessel having a concave bottom and adapted to contain molten metal to form the crucible, heating means in the wall of the vessel, a, jacket spaced from the "sides and bottom of the vessel, the said space being adapted to contain oil, and means for rotating the vessel, said means being mounted in the space below the bottom of the vessel, whereby said means will be lubricated by the oil in the said space.

6. Anapparatus for forming liquid crucibles, comprising a vessel providedwith a refractory linin having a concave bottom, an electrical con uctor embedded in the refraclining, a jacket spaced from the vessel -ductor int c sai member, a cooling jacket spaced,-from the\vessel, and means for roj tatin the ,vessel; Q 7

8. n an fapparatus for forming liquid crucibles, a rotatable vesselprovided with a refractory lining having a concave bottom adapted tocontain molten metal to form the crucibles, electrical conductors embedded in the lining, andcontacting rotary and fixed ring-like members, the conductors bein con nected with the rotary member, an the fixed member connected with an electrical suppl 9. 1X1 an apparatus for forming liquid crucibles, a rotary vessel provided with a refractory lining having a concave bottom and an annular inwardly projecting member, passsages being formed between the member and the body of the lining and opening at their ber of the lining, rotary and fixed ring-like members below the vessel, and means for holding said members in electrical connection, the rotary members being connected with the conductors and the fixed members connected'with an electrical supply. 10

The foregoing specification of our centrifugal liquid crucible signed by us this 8th day of October, 1926.

JUVENAL MAXIMOFF. MARIA STELLA de COSTA, ne VINCENT. 

